Radiotelegraphy



May 8, 1923. 1,454,630 H. F. ELLIOTT RADIOTELEGRAPHY Filed June 6, 1921 -IJ i WITNESS INVENTOR Off [Z0077 ATTORNEYS Patented May 8, 1923 entree-stares raranr caries.

.HAROLD r, ELLIOTT, or PALO ALTO, cauronnm, ASSIGNOR TO nuGUsTusTAYLon,

OF SAN FRANCISCO, CALIFORNIA.

BADIOTELEGRAPHY.

Application filed June 6,

To all whom it may concern:

Be it known that I, HAROLD F. ELLIOTT, a citizen of the United States, and a'resident of Palo Alto, Santa Clara County, State of California, have invented certain new and useful Improvements in Radiotelegraphy, of which the following is a specification.

The invention relates to radio telegraphy signaling systemsand particularly to single wave signaling systems, in which the source of oscillations is connected to the antenna circuit andto a local oscillating circuit, the electrical constants of the two circuits being such that the oscillations may be caused to prefer one circuit to the practical neglect of the other. Systems of this nature are particularly advantageous in continuous undamped wave signaling, in which the source of oscillations is an are or other continuous undamped wave generator. In systems of this type, the current in the antenna is reduced to relatively low values during the intervals between the dots and dashes of the signal.

It is an object of the present invention to reduce the magnitude of the residual current in the antenna during such intervals tosmaller values.

The invention possesses other advantageous features, some of which, with the foregoing, will be set forth at length in the following description where I shall outline in full, that form of the invention which I have selected for illustration in the drawings accompanying and forming part of the present specification. In said drawings I have shown my invention embodied in a single wave signaling system employing a Poulsen are as the source of oscillations, but it is to be understood that my invention is not limited to such system.

Referring to said drawings:

Figure 1 is a diagrammatic representation of a single wave signaling system embodying my invention.

Fig. 2 is a diagrammatic representation of a signaling system embodying a modified form of my invention. v

The signaling system shown comprising a source of continuous oscillations, preferably a Poulsen are 2, supplied with current from a suitable generator 3 and subjected to a strong transverse magnetic field produced 1921. Serial no. 475,513. I

is effected by transferring the output of I this may be accomplished in several ways, i

as by the signaling key 10, which operates to simultaneously open one slgnaling circult l2 and close the other signaling circuit 13 or vice versa. With these conditions existing, it has been found that a residual current remains in one circuit when the arc is oscillating on the other circuit and it is an ObJGCt of this invention to reduce the residual current.

In accordance with my invention, I couple the antenna and local oscillating circuits and thereby reduce the residual current in either circuit, when the arc is oscillating on the other. The circuits are coupled by the. variable coupling transformer 14, one coil of which is arranged in series in the antenna circuit and the. other coil of which is arranged in series in the oscillating circuit, and the coupling between the circuits is adjusted to produce the minimum residual current. Using the proper amount of coupling between the O1ICU1i3S, tl1e residual current is reduced to a'value below that which exists without coupling.

In the system shown in Fig. 2, means are provided focontrolling the phase angleof the voltage induced in the antenna circuit, by current in the local circuit. local circuit is divided into two branch circuits, oneof which contains a coil ofthe coupling transformer and a resistance 15 and the other of which contains a 'reactance 16. By suitably choosing values of resist- The ance and reactance in these branches, the 5 phase of the currents in thetwo branches may be regulated, and the voltage'induced in the other circuit by the couplin transformer is brought to thephase angl e which gives minimum residual current.

vention is not limited to the means shown.

I claim 1. A radio telegraphy signaling system,

comprising a source of oscillations, anantenna circuit connected to the source, and an oscillatory circuit shunted around the source and coupled to the antenna circuit.

v 2. A radio telegraphysignaling system comprising a source of oscillations, an antenna circuit connected to the source, an oscillatory circuit shunted around the source and coupled to the antenna circuitand signaling means for varying the electrical constantsof one or both of said circuits.

A radio telegraphy signaling system comprising a source of oscillations, an antenna circuit connected to the source, an oscillatory circuit shunted around the source, a transformer coupling said circuits and signaling means for varying the electrical constants of one or both of said circuits.

4:. A radio telegraphy signaling system comprising a source of oscillations, an antenna circuit connected to the source, an oscillatory circuit shunted around the source, said circuits being tuned to the same frequency, means for varying the electrical constants of one or both of said circuits and a transformer coupiing said circuits.

5. A radio telegraphy signaling system, comprising a source of oscillations, an antenna circuit connected to said source, an oscillatory circuit shunting said source, means for varying the electrical constants of one or both of said circuits whereby prac tically all of the current from the source is diverted to one circuit and means coupling said circuits for further reducing the residual current in the circuit in which the smaller current is flowing.

6. A. radio telegraphy signaling system, comprising a source of continuous oscillations, an antenna circuit and an oscillatory circuit both connected to said source, signaling means operative to cause the source to oscillate practically entirely on one of said circuits. and a transformer coupling said circuits.

' 7. A radio telegraphy signaling system comprising a source of oscillations, an antenna circuit connected to said source, an oscillatory circuit connected to said source, said oscillatory circuit including two branch circuits, 9. reactance in one of said branch circuits, a resistance in the other of said branch circuits, means coupling said latter branch circuit with the antenna circuit, and

nes nceo means for varying the electrical constants of one or both of said circuits.

8. A radio telegraphy signaling system comprising a source of continuous oscillations, an antenna circuit and an oscillating circuit, both connected to said source, signaling means for varying the electrical constants of one or both of said circuits whereby substantially all of the current from the source flows to the oscillating circuit leaving only a residual current in the antenna circuit and means for impressing a voltage on the antenna circuit to produce, with the voltage from the source, a resultant voltage having a different phase angle than the voltage from the source.

9. In a radio transmission system having a source of radio frequency current, a transmitting circuit connected to the source, an oscillatory circuit connected to the source, and means for varying the relative electrical characteristics of these two circuits so tiiat the current from the source will prefer one to the other, the method of reducing the residual current in that circuit which is inactive, which comprises coupling the two circuits together, and varying the extent of the coupling until the current is reduced to a minimum. 1

10. A radio telegraphy signaling system comprising a source of oscillations, an antenna circuit connected to said source, an oscillatory circuit shunted around said source, said oscillatory circuit having a branch circuit coupled to the antenna circuit and means for controlling the relative phase angle of the current in the coupling coil with respect to the current through the source.

11. in a radio transmission system having a source of radio frequency current, a transmitting circuit connected to the source, an oscillatory circuit connected to the source, and means for varying the relative electrical characteristics of these two circuits so that the current from the source will prefer one to the other, the method of reducing the res' ial current in that circuit which is inactive, which comprises introducing an E' M. F. in that circuit opposing the flow of current therein.

12. In a radio transmission system, a source of radio frequency current, a trans mitting circuit connected to the source, an oscillatory circuit connected to thesource, means for varying the relative electrical characteristics of these two circuits so that the current from the source will prefer one to the other, and means for introducing into the inactive circuit an E. M. F. opposing the flow of current therein.

In testimony whereof, I have hereunto set my hand.

HAROLD r. ELLIOTT.- T 

